Since you have 2 movies you have to given each movie clip a seperate name and use the onRelease event for movieclips.
_root.myFirstMovieClipName_mc.onRelease = function() {
getURL("http://www.siesta.cat");
}
_root.mySecondMovieClipName_mc.onRelease = function() {
getURL("http://www.ipic.cat");
}
Peace
Mike
http://www.eclecticpixel.com